This invention relates to an electrical junction box providing mechanical support and electrical connection to a hanging appliance such as a ceiling fan or lighting fixture.
Typically in the prior art, ceiling junction boxes are fastened to supporting structure by fasteners inserted vertically into the supporting structure, and a hanging appliance is suspended from the junction box by vertical screw fasteners threaded into tabs bent inwardly from the depending sidewalls of the box. Inherently in such an arrangement, the junction box is not flush with the supporting structure but hangs below it; and the threaded tabs, being typically about 1/16th inch thick, provide limited structural strength to the screw fastening of a hanging appliance.
In 1987, the National Electrical Code was amended to prohibit the use of a standard electrical junction box as the sole support of a ceiling fan. Junction boxes must henceforward be specifically designed and approved for that purpose.
It is an object of this invention, therefore, to provide an electrical ceiling junction box which is suitable both for flush mounting relative to a ceiling and for improved structural strength and integrity for mounting a hanging appliance.